C505_9708 SIEMENS [Siemens Semiconductor Group], C505_9708 Datasheet - Page 32

• Manufacturer Part Number: C505_9708
• Description: 8-Bit CMOS Microcontroller
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

3.5
The registers, except the program counter and the four general purpose register banks, reside in
the special function register area. The special function register area consists of two portions : the
standard special function register area and the mapped special function register area. One special
function register of the C505 (PCON1) is located in the mapped special function register area. For
accessing the mapped special function register area, bit RMAP in special function register
SYSCON must be set. All other special function registers are located in the standard special
function register area which is accessed when RMAP is cleared (“0“).
The registers and data locations of the CAN controller (CAN-SFRs) are located in the external data
memory area at addresses F700 H to F7FF H . Details about the access of these registers is
described in section 3.4.1 of this chapter.
Special Function Register SYSCON (Address B1 H )
Bit
RMAP
–
As long as bit RMAP is set, mapped special function register area can be accessed. This bit is not
cleared by hardware automatically. Thus, when non-mapped/mapped registers are to be accessed,
the bit RMAP must be cleared/set respectively by software.
All SFRs with addresses where address bits 0-2 are 0 (e.g. 80 H , 88 H , 90 H , 98 H , ..., F8 H , FF H ) are
bitaddressable.
The 52 special function registers (SFRs) in the standard and mapped SFR area include pointers
and registers that provide an interface between the CPU and the other on-chip peripherals. The
SFRs of the C505 are listed in table 3-2 and table 3-3. In table 3-2 they are organized in groups
which refer to the functional blocks of the C505. The CAN-SFRs (applicable for the C505C only) are
also included in table 3-2. Table 3-3 illustrates the contents of the SFRs in numeric order of their
addresses. Table 3-4 list the CAN-SFRs in numeric order of their addresses. .
Semiconductor Group
B1 H
Special Function Registers
Bit No. MSB
7
–
The functions of the shaded bits are not described here.
Function
Special function register map bit
RMAP = 0 : The access to the non-mapped (standard) special function
RMAP = 1 : The access to the mapped special function register area is
Reserved bits for future use. Read by CPU returns undefined values.
6
–
EALE RMAP CMOD
5
register area is enabled.
enabled.
4
3-11
3
2
–
XMAP1
1
Memory Organization
Reset Value : XX100X01 B
XMAP0
LSB
0
C505 / C505C
SYSCON
1997-08-01